Holley's Great Defect By Omission - Or, How To Fix That Mysterious Off The Line Stumble

[@MikeBrown-ii3pt]

I'm definitely not a newbie to carbs and you'll never hear me complain about carb videos. As a matter of fact, the more the better. I'm often reminded of little tricks that I've forgotten over the years. I didn't forget about jet extensions but, there have been other things.

[@paulbruno8327]

You’ll never hear me complaining about too many carb videos! Thanks again for another great video UT!!! 🏁

[@pete540Z]

Thanks, Tony. Damn, we're old (I was born in Apr 1962 - I think you were born in 62). I remember jet extensions and use them. Its wild to me that people wouldn't know about them!

[@allhailinternalcombustion]

Well you have to remember that there are 2 generations or so that were born in the days of fuel injection. Those poor people.......lol. And most of us that are older had a few head scratching moments trying to figure that bog out until we talked to someone.....in person......at a speed shop, or a magazine came out with carb tech.

[@pete540Z]

@@allhailinternalcombustion totally agree. FWIW, I'm converting the 406SBC in my 240Z to TBI EFI, replacing the carb.

[@johntierno546]

Some of the old school drag racers back in the 60s figured out how to battle this by mounting the carburetors sideways

[@benwamsley5876]

This is why I never miss an episode of utg!

[@moedog07]

Uncle Tony spends his time and effort to give his FREE carburetor knowledge away in his videos, and people complain. Shaking my head. Keep preaching knowledge UT. 0:03

[@The_R-n-I_Guy]

Fuel injection is pretty good. But I'm ready to simplify my life. I want a carburetor, points ignition and a manual transmission. No electronics. Not even electronic gauges. I'm sick of sensors and wires.

[@Bill_N_ATX]

Amen! And a one wire alternator too.

[@echota23]

Ultimately emp proof

[@superduty4556]

@@echota23 emp goes off and we have much bigger fish to fry than enjoying a classic car starting.

[@Ecosse57]

@@superduty4556 bugout vehicle.

[@echota23]

@@Ecosse57 yep and everyone else is walking

[@89ddx]

The drag race specific 4150s like the quick fuel carbs come with extensions. The other possibility that can cause problem is fuel slosh from the front bowl through the breather tube over the top. The solution is to add breather extensions into the bowl and to run a piece of hose from one breather tube to the other with a small slit in the top for air to get in. Fuel has to go much farther to slosh in

[@Sam-zp5rd]

Man I wish I knew that 30 years ago. I fought a stumble of the line with bigger accelerator pumps, and float levels but never could get it right.

[@omeyehead7436]

I had a dodge magnum with this problem. It was frustrating.

[@lowluv72]

I can never get enough of these pre computer carb and ignition videos

[@scottbrazinsky615]

Really admire this gentleman.The exact held true in 1982, as he explains here.Thank you sir.

[@nitrometh42]

I wish I knew this back in 1989....the last time I did any type of racing.....bogging off the line. Bracket racing, High school class.

[@racerx7319]

THANKS TONY I LEARNED SOMETHING I DIDN'T KNOW.

[@HeadFlowInc]

Jet extensions also require a notched float in the rear bowl. Highly recommended upgrade! 👍

[@josephsperrazza3082]

Tuning Carbs Brings Back Memories Of My Days As Young Kid Goose It And Masher , My Job Was Lay Across The Engine Bay With A Screw Driver And Yell Goose It Masher ,Never Had Problems With Bogg Outs Off line.

[@camaroguy2919]

You have mentioned this before briefly in another video. Thnaks for going into detail after your explination I can see how easy that would be to miss and throw money at the wrong area of the car.

[@victormiranda9163]

the first Carb Vid that made sense to me.

[@moparmatt5896]

This is why I love your videos! The little tips and tricks

[@christophersambuco9414]

I have an idea for an awesome carburetor tuning video (or even a little series of videos)... Install a wide band O2 meter, and do some real time test runs, and then show the methods to get the air fuel ratios right for hard acceleration throughout the RPMs, light acceleration and cruise. That would be some excellent content. 👌

[@herbnalis3723]

This has happened. Chevy Hi-Performance magazine did an article with a lap top/data logger/wide band sensor & drove & fine tuned the carburettor.

[@donaldshidal851]

I got so disgusted with Holley and their tech support, blown powervalves being replaced on the side of the road, hot intake manifold boiling the gas that spills out, glove box of powervalves and gaskets. I came to understand it as a POS. Went to an AFB, never looked back. Set it and forget it. Thanks Uncle Tony

[@hugechimp]

Ignore the haters. The carb vids are Fantastic! TY, Tony.

[@CAROLDDISCOVER-2025]

Thank you. I was never the carburetor man I guess lack of patience and desire. And the fact that my dad was great at it. Anyway he would dent the floats repair the floats if needed and put on his homemade jet extensions. So you're right forgotten knowledge. In my case I didn't ask when I had the opportunity to learn. But I gave racing up long time ago. But I've got my son's 57 Chevy sitting out here and his brother and I are going to put together and make at least one run down the quarter. Thanks for the update / reminder. It's just like on the channel when they called in the expert old guy to set the dwell on a set of points. As they said the laptops to one side and watch in amazement.

[@NeverMetTheGuy]

I don't even own anything with a carb, and still show up to this shit. It's just fantastic information.

[@timothyarnott3584]

Hey Tony, Tim here, yea, jet extensions for the secondary bowls is ESSENTIAL!!.....certain carb manufact. Know......my expensive QFT 950 for my Poncho, has them already!!.....essential for yer 60 ft......AED/QFT, offers carbs with extensions....NO FLOAT height band-aid......get a float relieved for them........GOTTA have them!!!......

[@zAvAvAz]

YesH thanks for this Uncle !

[@mrkrzt]

Love your knowledge. Old school thing.. I know the only time I learned something was a mistake and figure out why. No plug in scanner just experience

[@charlesgall7829]

Thank you. Priceless info not found in Holley books.

[@johndoe43]

If anybody cries or whines about your videos or content they have big problems. You always have good info with good delivery and intentions. As always thank you for your efforts

[@jonathanbush5024]

To add a note about vacuum secondary holleys. Holley makes a $60 lit to replace the jet plate with a metering block allowing for different jetting. The part number is 34-13.

[@TheCanadianBubba]

Just got my first 750 ! Thanks Uncle Tony 👍

[@frankc1430]

Excellent! More old school carburetor stuff.

[@patrickradcliffe3837]

11:57 Money, Money, Money Tony. They would have to retool and have two different valve bodies for the double pumpers.

[@benjaminmorgan6]

The carburetors that I use, thanks for the lesson

[@jdsimons6115]

Mine was a lean stumble soon as it opened and before the truck launched (C1500 chevy) this was confirmed with an AFR wideband. I did a couple of things, my fuel level is set to the middle of the sight glass in both bowls (4150 "brawler") Put .040 accelerator pump nozzles and put washers under the acc. pump adjustment springs to stiffen them up and the intake flange is angled forward a bit so it levels out better when the front end lifts. This cured 90% of it still stumbles a hair if i open it 100% from a dead stop. Havent gone to the extensions/floats still run the power valve.

[@haatch999]

hey something incredible is streetmachineTV is having this exact problem they thought it was heat soak or other things always bogs nearly dies at 10 ft mark then can run whole track rippen this video has helped so much already your the man tony

[@thisisyourcaptainspeaking2259]

What I like about carburetors most is I can go through one on a picnic table if need be. I prefer spread bore carbs. The best fix for any Holley is a Thermoquad.

[@340duster8]

I had to put a edelbroken on my Duster so I could rebuild the thermoquad. I did not realize on how badly it needed a full clean and rebuild until I changed carbs.

[@glennmanchester5696]

Or a quadrajet I am a gm guy so my go to is the quadrajet I knew guys w mopars and even they didn't really care for the thermoquad

[@340duster8]

@@glennmanchester5696 the quadrajet and thermoquad is a love/ hate relationship. The bad about the thermoquad is the bowls crack real easy.

[@ram2500pikup]

Thank you UTG!

[@kainhall]

ive also seen people use the wrong type of gasket on the power valve.... dude is just enriched the whole time LOL fixed that and rebuilt the card...... ended up with a LOYAL customer . im 28 and work in a 3 person CO-OP shop in NE montana...... not that many people left who know how (and want to) work on these older outfits . my favorite thing is using a vac gauge to tune for highest vac (idle mix and timing) for "granny driven" cars.... it just makes them run so smooth, with very little stalling and hesitation when cold . got quite a few LOYAL AF! customers that way . . . gotta love people who dont know GM made a 366 also LOL a 454 type block.... but only 366 cubes AKA indestructible (because of low power, yet WAY WAY overbuilt/strong/thick internals) . but VERY little info (or conflicting info) on the internet about them good thing i get old "tune up" books from the 50s to the 80s for my B-day and X-mas LOL i HORD thows old books lol

[@shoominati23]

I've run roadrace cars where we fit the double-wedged floats and those jet extensions, also we join the 2 float vents together with one of those offroad vents with the holes in the top.

[@HomeTipsAndTricks]

The carb videos are just great. I Thought I had a handle on Holleys. Your info is just plain great stuff! Thanks UT!

[@brianalbrecht4423]

U.T....never stop with carb videos ....!..the more info u put out there the more people will stay with carb's insted of e.f.i....GREAT video....thanks ...Brian

[@jonmoore8995]

Love Old School stuff. Got a lot from this.

[@craighansen7594]

A message to the ones complaining about too many videos on carbs. Even if you think you know it all, if you listen to another's take on things, you might learn/ re-learn something.

[@MrDibbons]

Back in the '70's I made sure to use the jet extensions in my 600 CFM Double Pumper (common procedure back then). Of course, launching a 4 speed @ 6,000 RPM with a 4.56 rear end ratio helped a lot to eliminate any chance of bog anyhow.

[@roadrunner4404]

Once we added ext tubes to the rear jets. Did it on a whim. The float couldnt drop down enough n it ran out of fuel at the top of second gear. Yes they make floats with twin cutouts but we took the ext off. Boss sold the car. Mild 350 in a vegan. 9 in slicks.

[@williamcharles9480]

Good job, Tony. Getting the average guy to understand carb theory is an art unto itself. Uncle, you are an artist.

[@anthonyjackson280]

Strong parallel with "Miss Shilling's orifice". For those unfamiliar, it is a great story of what today would be called 'a hack' but it greatly ameliorated a deadly carburetor design flaw in 1940.

[@hunnybunnysheavymetalmusic6542]

You COULD put a hand carved baffle over the top of the float... Just stick it to the top of the bowl. But yeah, jet extensions are certainly the way to go.

[@moyadapne968]

Uncle Tony has his Support The Pill T shirt on.

[@Hogiewan1]

Great info especially for an old timer like me. Many thanks

[@brianhdueck3372]

Always good info from UTG. Thank you sir.

[@hollowell427]

on the subject of metering plates. I bought a metering block kit from AED it changes it from a 4160 to a 4150.

[@thomasreaves588]

Once again, Thank you for sharing this wisdom of yours!

[@jameswaddington7913]

There are also jet extension tubes that press over the jet, still need to use notched float.

[@uasparts]

Yet another awesome carb tech instructional from uncle Tony! Great stuff, I’m 46 and quite advanced with carbs, but I learn something from every one of these videos just from the standpoint of performance.

[@hunnybunnysheavymetalmusic6542]

Rear bowls should have tubes that put the inlets on the back end of the bowl that always remain in the bowls. In other words, what we know as a jet extension should be standard parts for the rear bowls from the factory.

[@strokermaverick]

U.T. Great upload! Good info! Holley has been in the business, for thousands of years. That made me chuckle!

[@edge2sword186]

Remember ,Sam Colt made all men equal . Holley is Colt industries and they go way back before the autos were made.

[@joew8440]

You have a great way of breaking things down. You always make perfect sense

[@peggyparrow2059]

If you install extensions make sure they clear the float, or just get some phenpolic floats, and they make some with notches to clear extensions. Brass floats bounce and lose control of fuel metering.

[@rescuedandrestoredgarage]

I will always love the Carter style carbs. But for strip the Holly is best.

[@fairlanephantom]

Thanks again for your invaluable input Uncle Tony. I'm just running a Holley 2 BBL on my Ford V8 292, so I'm not taking my car to the track, but every bit of knowledge you share is great to keep in the back of my mind. On my car it had one plug that was getting hot, so I backed off the timing, I thought to balance that slight hesitation I ended up with at the accelerator pump adjustment on the adjustment at the throttle. Still had it, so I'm going to bring it up again. I have a small crack in the exhaust manifold that i think leans that cylinder out. One of the part carburetors i bought had an off road spring that I added to my carb. I've seen two schools of thought first said to make the float level, the other said to set the fuel height to a quarters diameter from the brim of the carb. Quarters width has worked much better, straight would flood every few trips. But anyway, I think that slight bump in the ignition timing can smooth things out as well. Just from the 10 -12 range I've been in makes a big difference. From a dead stop.

[@josephnowak]

One of the big feature differences between a 750dp and 850dp is the secondary powervalve (not talking about baseplate differences or main body differences just the fact that they added the pv). Yes its a no brainer to put a plug in the secondary side if you have jet size to go up... If you dont have room to go up you need the pv circuit. The secondary pv circuit is basically a useless feature with no extension available unless you make your own.

[@tommyhawks856]

Another excellent video, Tony.

[@EverythingHorsepower]

I’m a bit surprised you didn’t mention that you need a float that is notched for the jet extension

[@alstone5257]

where were you when i was 20, my 1970 GTX with a Holley was crap off the gate.haha

[@mattsgarage6670]

Just purchased a QuickFuel 750 brawler has the extentions from the factory kind of cool

[@martinsuter3531]

I'm older than you Tony but I just though using jet extensions was common knowledge. I guess maybe for younger guys it's not so common knowledge.. A r suggestion especially for the younger guys setting up and tuning a true a street/strip car with fa Holley carb and fairly radical cam, could you do a video on selecting the riight size power valves??

[@forthwithtx5852]

I bought a jet extension at Adam and Eve. She loves it.

[@ArthurSperotto]

I thought every race oriented Holley came with jet extensions? Maybe this is only a newer thing. My Holley Brawler Race 850 came with them.

[@xcellerated207]

I can't count how many times I changed accelerator pump cams, fattened the idle to eye watering, and countless other things, (including setting float too high) and wish I had known this in the early 2000's, I never fixed that stumble. Always chalked it up to the fact it was a weind x-celerator intake and too much cam.🤷

[@smilsmff]

yep they made a race kit at one time for all of that. and i used Fuel bowl extensions

[@malibuStroker]

The carb videos are awesome!!!

[@MsKatjie]

thanks for the valuable info., Uncle Tony . cheers

[@steveib724]

Always playing with this 650 Holley dp f it there's nothing else to do lmao 🤣 😂🤣🤣 see u Sunday going to try some of these tunes in spring

[@Charles_S.]

Great tip Tony👍

[@bigone721]

Not sure this is a forgotten thing. The last few 4 barrel carbs I've bought from Holley have come with jet extensions in a bag in the box.

[@speedy_pit_stop]

IOW it's optional. There must be a downside to using them on the street.

[@deanstevenson6527]

Jet extensions exist for those bizarre sideways mount 2300 2bbl 350 and 500 Holley's on the 200 and 250 log head six Ford's. They are great.Why not standard, well, the 4150/4160 and 4165/4175 effectively died in 1978 as an OEM carb. The 4180 that replaced it for 1979 as an OEM Ford truck 4bbl carb had the old side hanger bowl vent carb, and you didn't have jet extensions merchandized on those. Colt Industries and Holley needed GM OEM truck sales to get jet extensions. Instead, they had a really good Qjet.

[@jhonditch4269]

dad had a hell of atime trying to get a holley to work right never had a problem with carters

[@TheMadWookiee]

That’s how you sell tuning parts make them optional just like the vent whistle on the primary side

[@togst]

Interesting subject and another great explanation. I bought a classic car a year ago after being tempted by how they were supposed to be simpler to understand and work on. For the most part that has been the case, but the carburetor has given me grief from day one. I'm considering converting to fuel injection in order to "set and forget", as the constant tinkering is getting annoying.

[@donaldhalls2189]

Awesome, hope you had a great Christmas and wishing you all the best in the New Year

[@SPEEDOFDOG]

Now this here is pure gold!

[@shanerorko8076]

I'm happy with carburetor videos. I'm a mechanic by trade but I'm 34 so 99% of cars I work on are fuel injected. My daily is a Mitsubishi ute (Australian here) and it is carburetted but the Mikiuni that was on it was crap so I installed a Webber I think it's a 32 36 mech secondary and I have never had an issue. So I've never had to fix my carby, I did try and lean it up a little on accel drilling out the air bleed but it didn't really change so i left it.

[@blackcoffeegarage]

"You learn something new every day"... yeah, you do if you watch Uncle Tony! Wow!

[@MrJohnnyDistortion]

I get all choked up and feel fat whenever U.T. talks about carbs. 🤣😆

[@sydrider6023]

Nice subject to learn from, thanks and Happy New Hot Rod Year!🎉

[@KoryBrooks]

I have used power blast plates on the squirters on the last Holley I had and it was pretty awesome but I should have had jet extensions too.

[@stevefaltis8989]

By the time I got there, I used Edlebrocks. Hollers scared me

[@brucejones7389]

What about the sloshing on sideways mounted Holleys like on Slag hammer

[@deepinthought469]

Interestingly enough I started looking at my Edel1406 carb as the engine leans back about 5 degrees, that raises the fuel to the secondary jets and with a good launch I experience a rich bog and so maybe IT IS sloshing a squirt out the secondary jets, and I simply need a custom spacer to "level up" my carb. It's not a lot but 3 to 5 degrees to get level or 7 to 10 degrees (slightly tilted forward) for performance might give a little cushion...

[@bobsmith-mh7xz]

Complaining about carburetors….. give me a break! The carburetor is at least 1/3 of the things needed to make an engine run good again… it’s why we are here. Top tuned carb comes from lots of knowledge and testing… I for one appreciate having the differences explained and dissected..

[@frankglasgow]

Edelbocks new 4150 carb makes a lot of upgrades to the Holley

[@juniorwhelchel6337]

I'm so thankful for you and your videos I'm learning tons from you I'd love to know u personally wish u were closer to me here in Gaffney SC thank you UNCLE TONY

[@mrkultra1655]

Thanks Tony. Just goes to show you how many things can be fixed with a small piece of copper pipe.

[@WiSeNhEiMeR-1369]

HOWdy U-T-G, HOLLEY Carbs Thanks COOP the WiSeNhEiMeR from Richmond, INDIANA ...

[@BigT27295]

Good stuff Big T...

[@thewholls7176]

Good on you, uncle Tony I think it’s fair to say the reality is carbies make more power but I think you’ve done a video on that previously the whole thing with fuel injection is emissions control and mums and dads can have easy cold starts and they run okay stone cold…..

[@Jonhobbs64]

I recently bought a Holley HP 1000 carburetor and it had a small ziplock bag with jet extensions in the box and I had no idea what they were for. Now I know!! Thank you for all the killer explanations and knowledge! I'm going to take a look at my Holley carburetor book I bought 25 years ago and see if there's any mention of jet extensions.

[@2000freefuel]

Hey Tony could you cover the Harley CV carb, for tuning tips Tnx!

[@autonomous_collective]

AED PERFORMANCE Holley Carbs has been selling these extensions and more, for years. In my opinion, the AED Holly carbs are the best on the market. Check out their kits and carbs.